Re: [rtcweb] JSEP: Relaxing SDP O/A rules?

Martin Thomson <martin.thomson@gmail.com> Fri, 05 October 2012 17:14 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 93EEC21F8604 for <rtcweb@ietfa.amsl.com>; Fri, 5 Oct 2012 10:14:18 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.691
X-Spam-Level:
X-Spam-Status: No, score=-3.691 tagged_above=-999 required=5 tests=[AWL=-0.092, BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WhTSRsaytx5w for <rtcweb@ietfa.amsl.com>; Fri, 5 Oct 2012 10:14:18 -0700 (PDT)
Received: from mail-la0-f44.google.com (mail-la0-f44.google.com [209.85.215.44]) by ietfa.amsl.com (Postfix) with ESMTP id 9036221F85E6 for <rtcweb@ietf.org>; Fri, 5 Oct 2012 10:14:17 -0700 (PDT)
Received: by mail-la0-f44.google.com with SMTP id b11so1141140lam.31 for <rtcweb@ietf.org>; Fri, 05 Oct 2012 10:14:16 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=YKhMY48rMUGmMbxUoWw5yVqzrBKlOQwb1iiEP2s2nvo=; b=aMVbwBElpf7GOBFBjAOhYbsLvYe5Y1KMJdFKvN84Zwr1d5ryUxKDVSWLHgWC0T8aUH V0N9MwZ/YdeC6HeOttGg5MI52a3M7ORIi3/h/L/kd2+Nd927WTZP/4d4aeOiuZJ7kOQv vapaxV40cXf6dx5mSJl7fuWXLwEIoNYcLcnhlzEBuZyJ1ISPABdat85LAKKtxSj7qRFp 68ZOZwQPluUjGFtu0CFs8BoJA+w50XOQmUK7nGP22yr67MkzaYmhK51T8YvTIttzP1CM /oloTZXKwl7DKK8BLtXBO3M/iW9eksDZ7qvXL1lZmDqpBL/egcszh78zB7YzlzpzhDIh KXYQ==
MIME-Version: 1.0
Received: by 10.112.40.227 with SMTP id a3mr3902932lbl.91.1349457256563; Fri, 05 Oct 2012 10:14:16 -0700 (PDT)
Received: by 10.112.83.2 with HTTP; Fri, 5 Oct 2012 10:14:16 -0700 (PDT)
In-Reply-To: <7F2072F1E0DE894DA4B517B93C6A0585340A7BD0C5@ESESSCMS0356.eemea.ericsson.se>
References: <7F2072F1E0DE894DA4B517B93C6A0585340A1E3AB1@ESESSCMS0356.eemea.ericsson.se> <CABkgnnUFvw_J2+tvVBoHrzR9ZRkPT-6LhXvbaz_U1P7gqtJ4xw@mail.gmail.com> <7F2072F1E0DE894DA4B517B93C6A0585340A7BC848@ESESSCMS0356.eemea.ericsson.se> <CABkgnnV6NcTeh=L_fpkpLv5UpkUSuacmQUtYwNKKwAfcb5+JQA@mail.gmail.com> <506D4F7A.5020109@alvestrand.no> <CABkgnnUgHRw4dtihk2fZppmzVWuV4hpvWtXt70N1HWQpJ+KsZw@mail.gmail.com> <7F2072F1E0DE894DA4B517B93C6A05853409FF2FDF@ESESSCMS0356.eemea.ericsson.se> <CABkgnnV+jHWF3t8s3t37pbQyXJEP9N_MyHWd3SsfoNrhMU=NXw@mail.gmail.com> <7F2072F1E0DE894DA4B517B93C6A0585340A7BD0C5@ESESSCMS0356.eemea.ericsson.se>
Date: Fri, 5 Oct 2012 10:14:16 -0700
Message-ID: <CABkgnnVFWDroiTWVOm6F3FRQ6dDkRjKdyV8apRK=0Y_ReYtmPA@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
Content-Type: text/plain; charset=UTF-8
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] JSEP: Relaxing SDP O/A rules?
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 05 Oct 2012 17:14:18 -0000

On 5 October 2012 00:39, Christer Holmberg
<christer.holmberg@ericsson.com> wrote:
>>> If you want to support parallel forking, you need to be able to simultanously perform ICE etc with all remote peers.
>>
>> Right.  You can almost get that by pretending that it's just one
>> remote peer with lots of candidates.  You can at least get to the
>> consent point by doing that.  But you aren't going to nominate more
>> than one pair.  Similarly, this will only generate a single DTLS
>> session.
>
> I was thinking about the same once, but I think I found some issues (unfortunately they don't come to my mind at the moment).

It's probably not going to be flawless, true.  As you say, media would
be a little crazy.  You might be able to get one media stream out of
it - not multiple.

> Can I use the same local descriptor for every setLocal() call?

My experience suggests that you can.  However, that's not stipulated
in the API specification, so it's not an ironclad guarantee.

> Can you then at least tell me when I'll be able to buy the Microsoft Surface? :)

Yes.  When they release it.  October 25 apparently.